No matter what ive tried, anytime i try to play co-op on portal it simply says I, or my partner have disconnected. This often occurs at the final loading screen where the level is about to begin. It used to work fine about a month ago when i last played. Ive tried friends and random online partners -Trouble shooting ive already attempted:- I am up to date on downloads, - reinstalled portal and steam- no firewall active.

Same, me and my friend are not able to play online co-op. Send invite>accept invite>go to loading screen, one of us gets stuff in the loading screen showing 1 dot of 'loaded data' while the other sees 'your partner has diconnected'.

completely agreed unclebuddy. Not everyone understands the slang and terms used in computers. If I started using the terms used in my business, although it would be obvious to others in my profession everyone else would be lost. When talking to a layman I make it useable for everyone. What's the point in making others feel stupid. And if you can't explain it in common terms don't bother answering the question. If I knew what all that meant I'd likely know how to fix the issue!